Latitude E6440, stops charging, port hot and sparks when Battery is above 50% and turned ON

First, is the AC adapter recognized by the system?  F2 at powerup to check.

Isolating the cause starts with disconnecting the battery from the mainboard -- does that solve the problem?  If not, try another OEM adapter and see if it does.

If the problem continues and isn't battery or adapter related, the mainboard is likely the source of the problem.

@ejn63​ yes the laptop detects the charger as normal, and I've tried using it without battery, and yes it doesn't spark when I do so, I also tried using another battery and it still sparks with it too, but it doesn't spark or overheat when the laptop is sleeping or turned off, that's the weird part

It sounds like you have a mainboard issue -- that will almost certainly need to be replaced.

i  just noticed this now while trying to restart the PC,

@Xxmachina​ but after turning it off it detected the charger as normal, it seems unstable  

It would greatly help to know the specific system model -- Latitude E5430, 5330, etc.

There are still multiple possibilities, but if the issue continues with no battery (or another battery), the battery isn't the (sole) cause.

It may be worth trying a new OEM AC adapter and if the DC jack is replaceable, that next.  If neither solves the problem, replace the mainboard.

It'sDell latitude e6440

You can find complete, working E6440 systems are as little as $50 -- so it may be better to purchase a working system than trying to repair this one.  It won't take long before the parts add up to more than that.

@ejn63​  i borrowed my friends charger he's also using a dell but his charger is 65watt, and his charger is working fine although it charges slowly, compared to mine that is 90watt 

I also noticed that my charger plug gets burning hot in metal contact when in use,
while my friends charger just gets warm albeit being 65watt,
so I'm starting to think my charger is the problem maybe it's failing

A new 90W or higher OEM adapter is in order -- do not use the existing one until you've replaced it.

@ejn63​ is it safe to replace it with a 130watt OEM adapter?

Yes.  The system will only draw as much power as it needs.

That sounds serious and could be dangerous. The sparks and heat usually mean a bad charging port or a faulty charger. I’d stop using it for now and get the port checked or replaced by a technician, and maybe try a different charger to rule that out. Safety first.